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Vol. 10 No. 4 - October 2004

Vanishing Tertiary Genetic Heritage in the

East Mediterranean, Liquidamber Orientalis Mill.

By: M. Ozturk1, C. R. Parks2, F. Coskun3, G. Gork4, O. Secmen1

Very few people comprehend the importance and meaning of biodiversity; a common buzzword of these days. Habitat loss and genetic erosion are mainly responsible for the loss of our biodiversity leading towards species extinction. Most of the interpretations make a mention of this term as species diversity, including a plethora of living organisms and their habitats. However, ecologically it is an attribute of three other levels of biological organization namely; genetic diversity, community diversity and landscape diversity. In any case whenever we think of the quantitative side of this theme we start with number of species. Turkey with a population of 67 million inhabitants embodies more than 9000 taxa of pteridophytes and spermatophytes, including over 3000 endemics. This makes it one of the important plant diversity hotspots in the Mediterranean basin as well as Europe. The medicinal, agricultural and consumptive use values of this diversity together with their involvement in biogeochemical cycles, prevention of soil erosion, ecotourism, and regulation of climate provide the very basis of a countriy’s socio- economic development. We are losing 24-100 species a day due to habitat loss, introduction of alien species, pollution and over exploitation. The species extinction is proceeding at such a high rate that coming generations can face serious consequences. Liquidambar orientalis an east Mediterranean element with a boreal tertiary origin is one among such species facing a threat of extinction.

The oriental  sweetgum, Liquidambar orientalis Mill. is a tertiary period relict endemic taxon of the East Mediterranean, distributed naturally only in the South and West Anatolian parts of Turkey, mainly on sandy soils, with a high pH. The monoecious trees form dense forests  confined   to  floodplains, valleys and along streams and in a few dry habitats. In Turkish it is called “gunluk” due to the fragrance of the trees or “sigla” because of the gum like exudates, which has been used for more than seven hundred years as an all purpose drug, in particular as the most effective cure for stomach ulcers.

The name Liquidambar is said to have been given by Monardes in the 16th century as the name of the resin obtained in Mexico from the American species, now L. styraciflua.

The balsamic resin is collected from March till September every year from the trunks of about 10 years old trees with a girth of 15 cm. In Turkish it is called gunluk due to the fragrance of the trees or sigla because of the gum like exudate which develops in response to injury, being thus more a pathological than physiological response. The balsam containsα-pinene, β-pinene, myrcene, camphene, limonene, 1,8-cineol, p-cymene, terpinolene, linaool, 4-terpinenol, α-terpineol, dihydrocoumarone, cinnamic aldehyde, trans-methyl cinnamate, 1-benzoyl-3-phenylpropyne, β-phenylpropionic acid, benzoic acid, palmitic acid, and linoleic acid (12,37). The residual bark left after the extraction has been named as cortex thymiamatis, cortex thuris and storax bark. The resin is soft, viscid semi-liquid, grayish to grayish brown in color, semi-opaque, with a honey like consistence, balsamic odor, and pungent, aromatic, burning taste. It has been confined with a similar product obtained from a typical Mediterranean macchia element Styrax officinalis in earlier times. Later on term styrax was used for the resin of Liquidambar and storax for that of Styrax officinalis.

The early history of the resin is a little mixed up, but it surely goes back to Theophrastus and Herodotus (Hus 1949). An authenticated record clearly gives its use somewhere in 629 A. D., which refers to Chinese sources as well as to the name zygia (12,26). In the 7th century Su Kung has written about the drug named as su ho hiang which is a kind of styrax coming from western Asia ( 38). Chinese have mentioned about Liquidambar exudate as an excrement of lions as well as a symbol of tranquility and perfume to expel evil spirits. The wood of Liquidambar has been used to make tea chests in China. It also has been used to make  idols due to the  waving of branches and fluttering of leaves in the wind which led Chinese to a belief that this tree is inhabited by spirits. Due to its incense characteristics, it is used even now in mosques and churches in several countries. According to Kang Mu ( 26) styrax was considered as a cure-all drug in the Chinese medicine, to treat ulcers, hemorrhage, toothache, scales, swellings, some of the cancerous outgrowths, improvement of circulation and healing of wounds as well as cuts. A similar use has been put forth for root and leaf preparations. Other medical sources of 16th century however, have not been referring to all these cures. Styrax of course has served as an important   drug for seven hundred years. It has been used as an expectorant in asthma, bronchitis, and lung infections, in fumigatories, incenses, perfumes and skin diseases. The bark is said  to have been used to cure colds, diabetes, dysentry, cholera and dropsy (38). Chinese literature also cites the preparations from the fruits to cure back-aches, spasms, eye clearing and prevention of plague. Out of this large list of cures the only one left behind today is treatment of ulcers under the name storaxol (26) and its use in compound tincture benzoin. It is also used in adhesives and tobacco industry. The resin which develops in response to injury, more a pathological response than physiological one, is consumed directly even now in Turkey to treat ulcer. It is sold at the market in Marmaris area.  One teaspoon of the resin is mixed up with one teaspoon of honey and taken directly with empty stomach daily in the mornings for 10 days. The residue left after resin pressing is used as an incense in mosques. Lately the production of the resin in Turkey has however, diminished tremendously from 180 to 1 ton due to its less use and destruction of these relict forests.

Threats to extinction: The forests of L. orientalis have been severely destroyed during the  last 200 years. This disappearance has started the chain of events leading to an extinction of many other species. Unfortunately, the landscape is becoming increasingly fragmented leading towards a loss of too many species, which means a psychological and spiritual loss too. There is an urgent need for sustained maintenance of these forests for scientific, utilitarian, and ethical purposes. The fragrant aromatic balsamic resin appears to keep the insects and fungi away from the healthy populations of oriental sweetgum. In fact these forests have suffered much from the anthropogenic pressures than insect attacks. Major factors involved in the destruction of this important genetic heritage are cutting and felling for field openings and settlements. This practice has continued for over 200 years. Earlier, Egyptian experts living around Nile delta were despatched to this region during Ottoman Empire to drain these swampy areas in view of their know-how in this field. During last few decades the trees are first cut followed by planting fast growing Eucalyptus globules, which dries up these areas. Latter plantations are felled then and citrus orchards established. These orchards are maintained whence they are taken over by land speculators for constructing summer residential quarters, since a major part of these forests lies near to the coast on the Aegean and Mediterranean Sea. In addition, use of these forests as grazing grounds because of the rich herbaceous undercover as well as inflicting injuries through deep and long cuts for the procurance of resin add to the major destructive activity cited above. The trees used for the exudates production live for 30 years but untouched trees live for more than 100 years.

Bark Pollution: The bark of trees growing along roadsides was observed to be darker in colour than those away from the highways. The thickness of bark of the trees in unpolluted sites in the states of  Antalya, Isparta, Denizli, Aydin and Datca was recorded as 0.9 -1.1 cm and bark  pH at these sites varied between 4.3–6.6,  whereas thickness in medium polluted sites like Yatagan, Milas and Marmaris in the state of Mugla was 1.3-1.4 cm and pH of the bark samples was 3.3-4.7. In the highly polluted samples collected from the trees alongside the highway passing through Koycegiz bark thickness was 1.5 cm and pH varied between 2.8-3.7. In the latter area very low epiphytic and ground plant cover was observed in the forests along the highway. This can be attributed to the pollution due to leaded gasoline originating from the heavy traffic.


Conclusions: The area of this taxon has got reduced from 7000 to 1657.80 ha during the last 200 years. Major anthropogenic impacts involved in the decline of this important genetic heritage are habitat destruction due to cutting and felling for wood, followed by a change of the land use, grazing, resin extraction and urban development pressures. The loss of this precious genetic resource has been increasingly more in the recent past mainly due to degradation and shrinking habitat and often their complete loss due to cutting, summer house constructions, tourism and land acquisition for agricultural purposes. This problem is acute in the Mediterranean, due to increasing chunk of area being used for tourism. There is an urgent need for its in situ conservation. Although some protected areas have been earmarked but the preservation and restoration of these open spaces is insufficient to maintain and rebuild biodiversity. There is an urgent need for an international support as well for maintenance of this area as an in situ conservation site as well as a world heritage site. This will help us to re-establish biological continuums in the L.orientalis  distributional zone. In Europe national and regional maps defining the networks of ecological corridors are expected to be set up until 2005. Like Europe the ecological network is the backbone of the biodiversity strategy for ecology and  landscapes in the Mediterranean basin too. But the countries bordering the Mediterranean are dragging their feet, as is often the case where protection of biodiversity is concerned. The species is shown as vulnerable (degree of threat) in the plants of Europe threatened tree Project. There is an immediate need for a protection of the forests of  this  plant species through in-situ conservation. In situ conservation of special, vulnerable ecosystems is essential. These include all habitats with emphasis on mountains, wetlands and deserts. Many of their representative areas are now protected. According to IUCN report these protected areas numbering 9800 cover 92,63,49,000 ha area of earth surface. Immense possibilities exist for in‑situ conservation L.orientalis. Since it is a common property resource, active involvement of local people in their management will always be a pre‑requisite for their better management and conservation.

1M. Ozturk and 0. Secmen, Botany Department, Ege University, Bornova - Izmir, Turkey

2C.R.Parks Biology Department, The University of North Carolina-Chapel Hill, N.C., USA

3F. Coskun, Biology Department, Balikesir University, Balıkesir, Turkey

4G. Gork, Biology Department, Mugla University, Mugla, Turkey

This article has been reproduced from the archives of EnviroNews - Newsletter of ISEB India.

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